As a fire officer you have been given the responsibility under the law to understand, guide and direct a hazardous material emergency. O.S.H.A. and EPA both address a minimum training requirement for anybody commanding a hazardous material incident. The law states, Incident commanders, who will assume control of the incident scene beyond the first responder awareness level shall receive at least 24 hours of training equal to the first responder operations level and in addition have competency in the following areas and the employer shall so certify:

(A) Know and be able to implement the employer's incident command system.

(B) Know how to implement the employer's emergency response plan.

(C) Know and understand the hazards and risks associated with employees working in chemical protective clothing.

(D) Know how to implement the local emergency response plan.

(E) Know of the state emergency response plan and of the Federal Regional Response Team.

(F) Know and understand the importance of decontamination procedures.

Considering the complexity of a chemical emergency, and the spilt second decision making that is required during the incident, the fire officer needs a simple system that will guide him through the incident. By asking the following questions, What is the product involved? How will the product hurt my personnel the public or myself? And lastly is there enough of the product there to hurt me? With these three questions answered the officer in charge can begin to gain control of the situation. Prior to answering these questions the fire officer's first consideration should be the safety and security of the site. Once zones have been established and assessment begins, the first question to be asked is ...What is the product? As a fire officer you should be very comfortable with the various types of clues that can be used to identify a hazardous materials presence. The National Fire Academyís program ìRecognizing and Identifying Hazardous Materialsî as long as ten years ago provided us with the six clues for identifying hazardous materials that can still be used today.

OCCUPANCY AND LOCATION
Under SARA Title three many of the specific sites in your community have been identified and pre-plans have been written. If you as an officer have never seen nor reviewed your communities' hazardous material plan this would be an excellent place to start. In addition you should be alert to the obvious locations in your communities that utilize hazardous materials such as laboratories, factories, farms, paint supply outlets, service stations, and construction sites. If KA-BOOM Chemicals were in your first run district as an officer I would be darn sure I knew of the hazards and the exposures that could be encountered. A visit to the plant would be very beneficial.

CONTAINER SHAPES AND SIZE
In World War II airplane pilots studied silhouettes of the shape and size of the enemy ships and planes in order to familiarize themselves with the enemy. With the enemy in HAZ-MAT response being the chemical it is essential that a fire officer recognize the products, and their associated hazards by their container. DOT regulates certain shapes for the transportation of hazardous materials. Stationary bulk storage containers at fixed sites, bulk transport vehicles such as rail and truck tank cars and smaller quantities of Haz-Mats transported in fiberboard boxes, drums, or cylinders. You as the company officer must become intimately familiar with the types, kinds and construction features of the containment systems.

MARKING AND COLORS
Transportation vehicles must use DOT markings; some require specific identification numbers. Identification numbers, located on both ends and both sides, are required on all cargo tanks, portable tanks, rail cars, and other small packages that carry Haz-Mats. Another system widely used in fixed site is the N.F.P.A. 704 marking system. This system utilizes a diamond divided into four quadrants. Each quadrant represents a different type of harm, the left blue section refers to the health effects, the top, red quarter pertains to the flammability of the product, the yellow right section refers to the products reactivity and the bottom white quadrant highlights special information. In larger facilities they may have their own system in place of, or an adaptation of the 704 system. This system rates products on a scale from 0-4. Four designates the highest danger.

SHIPPING PAPERS/M.S.D.S. SHEETS
In the transportation of hazardous materials the shipping papers play a vital role in the identification of the exact products you the officers are dealing with, These papers contain the shipping name, hazard class, ID number, quantity, and may indicate hazardous waste or a poison. The shipping papers will also clarify the dangerous placard shipment. In the discussion of paperwork associated with chemicals the officer must consider the M.S.D.S. sheet. The information on these sheets was designed for the worker in the work place but will provide valuable information during a hazardous material emergency. Under the SARA legislation the role that the M.S.D.S. sheet has been expanded. Today the M.S.D.S. sheets are used as a reporting document and as a planning tool. The information provided on these sheets is so useful that during several actual emergencies I had them faxed to our fire station during the emergency, thus providing the information that we needed.

YOUR SENSES
Odor, dead animals or fish, fire, a visible cloud, a pursing hiss, and irritation to the skin or eyes can signal the presence of a hazardous material. An important consideration in dealing with chemicals is the fact that some can impair an individual's sense of smell, others have no smell at all, and some by the time you smell them some harm has occurred.

The second consideration as an officer is how does the product hurt ME! For the purposes of this article we will look at the type of harm that can occur right now. O.S.H.A. has defined three types of harm that can effect you immediately. They are flammability, oxygen deficient atmospheres and toxic environments. Prior to the discussion of each one of these consider when does harm occur. Harm occurs from direct contact with the substance or from products that produce vapors. Vapors can be directly related to the type and amount of harm that will occur. The weight of the vapors (vapor density) and the forces that the vapors are coming at you (vapor pressure) are key elements in a hazardous material incident. High vapor pressure products may require large evacuations and dictate the need for high level of protective equipment.

If the product has a vapor pressure of less than 760 mm/hg, 1 atmosphere, or 14.7 psi than the product will be a liquid or even a solid. As an example the vapor pressure of sulfuric acid is 1 mm/hg at 295&Mac176;F, thus sulfuric acid is a liquid that has minimal evacuation associated with it and may be handled with level B (skin by contact) type of protective garments. The vapors have no driving force behind them. Vapor pressures greater than 760 mm/hg, 1 atmosphere, or 14.7 PSI the products will be a gas. A product with a high vapor pressure is chlorine; it has a vapor pressure of 10 atm. (150 psi) at 68 &Mac176;. Chlorine has the ability to move thus large evacuation zones are needed, and because it is coming at me at a high-pressure high levels of protective garments (level A entry suits) are needed.

As a fire officer you should be very familiar with the harm that can occur from fire. Flash point is the minimum temperature of a liquid at which it gives off sufficient vapors to form an ignitable mixture, fire point the lowest temperature of a liquid at which vapors are evolved fast enough to support continuous combustion and auto ignition temperature the minimum temperature to which a substance must be raised in order to ignite must be considered.

The next consideration in a flammable atmosphere is the concentration of the vapors. In order to have a fire I must have a minimum amount of fuel to air ratio. This minimum amount of product in air is called the Lower Explosive Limited. The LEL of a vapor or gas; is the lowest concentration that will produce a flash fire when an ignition source is present. At concentrations lower than the LEL, the mixture is too "lean" to burn. This is your first goal post. If we have a minimum amount of vapor in air then we can also have a maximum amount of vapor in air. The UEL of a vapor or gas; is the highest concentration that will produce a flash of fire when an ignition source is present. At higher concentrations, the mixture is too ìrichî to burn. This is the second goal post. The area between the two goal posts is the flammable range. Products with wide flammable ranges and low LEL present the greatest danger.

The second type of harm that can occur is an oxygen deficient or enriched atmosphere. In air the normal amount of oxygen is 21%. This percentage can be increased or decreased to levels that can cause immediate harm. Products with high vapor pressures and high expansion ratio's will force the oxygen out and create an oxygen deficient atmosphere. Under O.S.H.A. law if an atmosphere's oxygen has been reduced to 19.5% or increased to 23.5% this is considered immediately dangerous to life and health. At the 19.5% level the oxygen has been diminished substantially that the law requires that self-contained breathing apparatus MUST BE WORN.

The third consideration is the toxicity of the product. This includes is the product an inhalation hazard, a skin by contact hazard or a skin by absorption hazards? One of the fastest ways to toxify an emergency responder is by inhalation. The inhalation of a product can occur remote from the spill area and effect all of the responders (remember that everyone must breath) In all chemical emergencies it is critical that self contained breathing apparatus be worn at all times. Skin by contact usually happens when someone gets to close to the chemical. This might happen prior to your arrival as in a citizen exposed or may involve one of your crew that has come in contact with the spilled material. Skin by absorption may produce systemic effects, including cancers, teratogens and mutagenes. With skin by absorption chemicals a higher level of protection is an option to be considered.

Although we focus on the big three flammable, 02 deficient and toxicity of the products it must be noted that other types of harm might be present. Trip and fall hazards, exposure to the elements, sharp edges and tight working quarters may be present at the site.

The last question to consider is ìIn what concentration does the product exist? Or is there enough present to cause harm?" Truly the only definitive way to answer this question is through the use of air monitoring equipment.

In the discussion of concentration we could classify these atmospheres as safe, unsafe and dangerous atmospheres. Many responders today will want a definition of ìWhat is Safeî and argue that all chemicals in a high concentration or over long periods of time will eventually do some harm. Safe concentration can be found in chemicals that are being used in there intended manner, possibly emitting vapors that are below toxic levels that various agencies have established, below 20% of the products LEL, or has not affected the amount of oxygen content in air.

Unsafe atmospheres can happen when an emergency exists and there is a potential threat of release or actual chemical spills you may be in an unsafe atmosphere. It is very difficult to recognize or identify the unsafe atmospheres without a meter.

We will make a general assumption as emergency responders if it's spilled assume Unsafe. Unsafe atmospheres may dictate the isolation of an area, some form of respiratory protection, or some type of chemical protective clothing. Chemicals that are fast actors or deliver debilitating injuries can generate unsafe atmospheres quickly. Exceed any of the recommended levels established by various agencies; you are no longer safe! Whenever you are exposed to levels of chemicals above the Ceiling, Permissible Exposure Limits, or Recommended Exposure Limits it has to be assumed that you are in an unsafe exposure, stay in it long enough and some form of harm will occur. Flammable atmospheres that have been monitored and have moved above 20% of the LEL uncorrected must be considered unsafe. Unsafe oxygen atmospheres are those atmospheres that have reduced the oxygen content from 21% down to 19.5%. Unsafe atmosphere must be treated with the utmost respect. Until adequate monitoring has been accomplished the emergency responder must assume that at the very least, there could be some unhealthy or unsafe exposure. He must be very cautious because he is rapidly approaching serious levels and extreme danger.

Dangerous atmospheres occur when concentrations begin to increase above these unsafe levels and a potential for life threatening injuries can occur. These high concentrations of any chemical are extremely dangerous to the responder's Life and Health. This level is defined as Immediate Dangerous to Life and Health. I.D.L.H. is as the maximum concentration that poses a threat for immediate death, or immediate injury or permanent adverse health effects. It is established as a limit so that a worker could escape without symptoms that would impair his ability to escape. The symptoms that would retard escape are -- 1) Blindness, 2) Unconsciousness, and 3) impaired judgment. In general this value although limited and conservative is a value that represents the maximum concentration workers could escape if their respiratory protection fails. Chemicals that have I.D.L.H.

Concentration valves have exhibited harmful effects when the concentration increases. They are debilitating in nature and in many cases lethal. If a chemical can ignite or has the potential for ignition it would certainly be dangerous to anyone's life and health.

Many chemicals that are flammable have two "IDLH's" Toxic and Flammable. It is a fact that when a chemical has reached its LEL it has been well above its (toxic) I.D.L.H. As any responder knows we need 21% oxygen to carry on normal activities. When this concentration drops below 21%, our ability to survive diminishes. Below 19.5 the first affected organ is the brain. You begin to have impaired judgment. Remember those oxygen contents below 19.5% are considered I.D.L.H.

Will a simple system work when dealing with the complexity of a chemical emergency? Armed with the answers to these questions, What is the product involved? How will the product hurt my personnel the public or myself? And is there enough of the product there to hurt me? You, the officer can make knowledgeable decisions that will favorably change the outcome of these incidents.